We've been to the following places with ours chris.
Northumberland - Bowden, back and other places I can't remember the name of, Gimmerknowe(?). Often short approach and flat and grassy at the crags. so really good for toddlers as an area - beach too.
Lakes - we stayed in the cottage by the campsite at eskdale. 30 seconds walk to the boulders, ideal as I could squeeze in climbing around a normal day. miniature train. bouldering not extensive but it's really nice. this part of lakes is a bit quieter.
Bowderstone for obvious reasons.
Can't think of any others.